Medical electrical stimulation systems typically include one or more conductors that extend within an elongate insulative lead body and are coupled to one or more electrodes supported by the body. The one or more electrodes are typically coupled to a distal portion of the lead body so that, when the distal portion is implanted in a patient's body, the one or more electrodes are positioned to provide electrical stimulation therapy, for example, pain-relieving spinal stimulation from electrodes implanted along a spinal cord within an epidural space.
One type of spinal cord stimulation system includes a single column of electrodes, which is coupled along a distal portion of a lead body and has a profile that facilitates percutaneous delivery through a needle to an implant site along the spinal cord within the epidural space. Another type of spinal cord stimulation system includes at least two columns of electrodes coupled to a distal portion of a lead body; the at least two columns are spaced apart from one another so that a profile of the distal portion is often paddle-like and requires surgical implantation, because the size of the distal portion is too large to fit through a needle for percutaneous delivery. These paddle-type electrode assemblies, having more than one column of electrodes, provide flexibility for selection from a variety of stimulation patterns upon implantation without having to physically reposition the assemblies within the epidural space.
Some spinal cord stimulation systems, which include more than one column of electrodes and which collapse into a smaller profile for percutaneous implantation, are known in the art. Yet, there is still a need for spinal cord stimulation systems that include more than one column of electrodes and are designed to further facilitate operator control over the systems during an implant procedure thereby increasing an ease of implanting the electrode columns at desired locations.